Note: This column was submitted by Indiana University President Michael A. McRobbie and Columbia University President Lee C. Bollinger. It appeared in the New York Daily News on Oct. 19, 2018.

Heading into this year's midterms, there’s no shortage of reports about potential threats to the machinery of our nation's most basic function of self-government — our elections. While we cannot know if Russia or some other actor might attempt such an intrusion, we actually do know how to guard against both intentional attacks and unintentional errors in how we count the votes Americans cast to determine our collective future.

At a time when more technology seems like the answer to almost everything, the key solution to protecting the integrity of future U.S. elections is deceptively simple. It’s a return to paper ballots — and manual audits — that can protect our democracy in the digital age.

Nearly two years ago, we set out to study the future of voting, together with some of the nation’s leading experts on elections convened by the National Academies of Sciences, Engineering and Medicine. At that time, long lines at polling places and outdated election equipment seemed to be the greatest threats our study would seek to solve.

But after the 2016 presidential election, we found ourselves facing a far different scenario. To be clear, ballot access and cranky equipment are still issues, but it quickly became evident that the far bigger challenge is foreign meddling.

As reports from the U.S. intelligence community indicate, actors sponsored by the Russian government targeted our election infrastructure in 2016, establishing and maintaining a presence in the election systems of multiple states. Top U.S. security officials have warned of the danger of further interference as we head toward November's midterm elections.

This threat is real and evolving. The federal government needs to work with state and local governments since they do not, on their own, have the capacity to protect their elections against attacks from foreign nations. We must continuously monitor and improve the cybersecurity of systems used in elections, such as voter registration databases and vote tabulation systems.

But even if best practices are applied, there is no way to guarantee that the technologies used in election systems are completely secure, given the evolving nature of cyberthreats.

That brings us to paper. Our findings have made increasingly evident that we need two additional protections that work together to verify and safeguard the integrity of elections: paper ballots and audits of election results.

Paper ballots, evidence of voters' selections that cannot be altered by faulty or compromised software or hardware, should be used whenever possible in the upcoming November federal election. By the 2020 presidential election, all U.S. elections should use paper ballots.

It is fine for voters to mark the paper ballots either by machine or by hand, and for jurisdictions to count them by machine or by hand; but what is most important is that there is a physical record of each voter's choices.

Fortunately, most jurisdictions across the U.S. already use paper ballots, or use electronic voting machines that produce a paper record, which voters can verify before submitting it for tabulation.

These ballots should be used in implementing the second safeguard we recommend: routine auditing of election results. Audits inspect a sample of paper ballots in order to verify that voters' selections were tabulated correctly and that the reported election results are accurate.

Paper may sound like yesterday's idea, but the future of our democracy may well depend upon it.